10/24/2016 CPK coloring ­ Wikipedia CPK coloring From Wikipedia, the free encyclopedia In chemistry, the CPK coloring is a popular color convention for distinguishing atoms of different chemical elements in molecular models. The scheme is named after the CPK molecular models designed by chemists Robert Corey and Linus Pauling, and improved by Walter Koltun. Contents 1 History A plastic ball­and­stick model of 2 Typical assignments proline. These models usually comply 3 Modern variants 4 See also with CPK coloring. 5 References 6 External links History In 1952, Corey and Pauling published a description of space­filling models of proteins and other biomolecules that they had been building at Caltech.[1] Their models represented atoms by faceted hardwood balls, painted in different bright colors to indicate the respective chemical elements. Their color schema included White for hydrogen Black for carbon Sky blue for nitrogen Red for oxygen They also built smaller models using plastic balls with the same color schema. In 1965 Koltun patented an improved version of the Corey and Pauling modeling technique.[2] In his patent he mentions the following colors: White for hydrogen Black for carbon Blue for nitrogen Red for oxygen Deep yellow for sulfur Purple for phosphorus Light, medium, medium dark, and dark green for the halogens (F, Cl, Br, I) Silver for metals (Co, Fe, Ni, Cu) Typical assignments Typical CPK color assignments include: https://en.wikipedia.org/wiki/CPK_coloring 1/6 10/24/2016 CPK coloring ­ Wikipedia hydrogen (H) white carbon (C) black nitrogen (N) dark blue oxygen (O) red fluorine (F), chlorine (Cl) green bromine (Br) dark red iodine (I) dark violet noble gases (He, Ne, Ar, Xe, Kr) cyan A box of ball­and­stick model pieces phosphorus (P) orange colored to represent several of the common elements. sulfur (S) yellow boron (B), most transition metals peach, salmon alkali metals (Li, Na, K, Rb, Cs, Fr) violet alkaline earth metals (Be, Mg, Ca, Sr, Ba, Ra) dark green titanium (Ti) gray iron (Fe) orange other elements pink Several of the CPK colors refer mnemonically to colors of the pure elements or notable compound. For example, hydrogen is a colorless gas, carbon as charcoal or graphite is black, common sulfur is yellow, chlorine is a greenish gas, bromine is a dark red liquid, iodine in ether is violet, amorphous phosphorus is red, rust is dark orange­red, etc. For some colors, such as those of oxygen and nitrogen, the inspiration is less clear. Perhaps red for oxygen is inspired by the fact that oxygen is normally required for combustion or that the oxygen­bearing chemical in blood, hemoglobin, is bright red, and the blue for nitrogen by the fact that nitrogen is the main component of Earth's atmosphere, which appears to human eyes as being colored sky blue. Modern variants The following table shows colors assigned to each element by some popular software products. Column C is the original assignment by Corey and Pauling,[1] and K is that of Koltun's patent.[2] Column J is the color scheme used by the molecular visualizer Jmol.[3] Column R is the scheme used by Rasmol; when two colors are shown, the second one is valid for versions 2.7.3 and later.[3][4] All colors are approximate and may depend on the display hardware and viewing conditions. https://en.wikipedia.org/wiki/CPK_coloring 2/6 10/24/2016 CPK coloring ­ Wikipedia Colors A# Sy Element C K J R 1 H hydrogen 1 2H (D) deuterium 1 3H (T) tritium 2 He helium 3 Li lithium 4 Be beryllium 5 B boron 6 C carbon 6 13C carbon 13 6 14C carbon 14 7 N nitrogen 7 15N nitrogen 15 8 O oxygen 9 F fluorine 10 Ne neon 11 Na sodium 12 Mg magnesium 13 Al aluminium 14 Si silicon 15 P phosphorus 16 S sulfur 17 Cl chlorine 18 Ar argon 19 K potassium 20 Ca calcium 21 Sc scandium 22 Ti titanium 23 V vanadium 24 Cr chromium 25 Mn manganese 26 Fe iron 27 Co cobalt 28 Ni nickel 29 Cu copper 30 Zn zinc 31 Ga gallium https://en.wikipedia.org/wiki/CPK_coloring 3/6 10/24/2016 CPK coloring ­ Wikipedia 32 Ge germanium 33 As arsenic 34 Se selenium 35 Br bromine 36 Kr krypton 37 Rb rubidium 38 Sr strontium 39 Y yttrium 40 Zr zirconium 41 Nb niobium 42 Mo molybdenum 43 Tc technetium 44 Ru ruthenium 45 Rh rhodium 46 Pd palladium 47 Ag silver 48 Cd cadmium 49 In indium 50 Sn tin 51 Sb antimony 52 Te tellurium 53 I iodine 54 Xe xenon 55 Cs caesium 56 Ba barium 57 La lanthanum 58 Ce cerium 59 Pr praseodymium 60 Nd neodymium 61 Pm promethium 62 Sm samarium 63 Eu europium 64 Gd gadolinium 65 Tb terbium 66 Dy dysprosium 67 Ho holmium 68 Er erbium 69 Tm thulium 70 Yb ytterbium https://en.wikipedia.org/wiki/CPK_coloring 4/6 10/24/2016 CPK coloring ­ Wikipedia 71 Lu lutetium 72 Hf hafnium 73 Ta tantalum 74 W tungsten 75 Re rhenium 76 Os osmium 77 Ir iridium 78 Pt platinum 79 Au gold 80 Hg mercury 81 Tl thallium 82 Pb lead 83 Bi bismuth 84 Po polonium 85 At astatine 86 Rn radon 87 Fr francium 88 Ra radium 89 Ac actinium 90 Th thorium 91 Pa protactinium 92 U uranium 93 Np neptunium 94 Pu plutonium 95 Am americium 96 Cm curium 97 Bk berkelium 98 Cf californium 99 Es einsteinium 100 Fm fermium 101 Md mendelevium 102 No nobelium 103 Lr lawrencium 104 Rf rutherfordium 105 Db dubnium 106 Sg seaborgium 107 Bh bohrium 108 Hs hassium 109 Mt meitnerium https://en.wikipedia.org/wiki/CPK_coloring 5/6 10/24/2016 CPK coloring ­ Wikipedia 110 Ds darmstadtium 111 Rg roentgenium 112 Cn copernicium 113 Uut ununtrium 114 Fl flerovium 115 Uup ununpentium 116 Lv livermorium 117 Uus ununseptium 118 Uuo ununoctium See also Molecular graphics Ball­and­stick model Software for molecular modeling References 1. Robert B. Corey and Linus Pauling (1953): Molecular Models of Amino Acids, Peptides, and Proteins. Review of Scientific Instruments, Volume 24, Issue 8, pp. 621­627. doi:10.1063/1.1770803 (https://dx.doi.org/10.1063%2F1.177080 3) 2. Walter L. Koltun (1965), Space filling atomic units and connectors for molecular models. U. S. Patent 3170246. 3. Jmol color table (http://jmol.sourceforge.net/jscolors/) at sourceforge.net. Accessed on 2010­01­28. 4. Rasmol color table (http://www.bio.cmu.edu/Courses/BiochemMols/RasFrames/CPKCLRS.HTM) at bio.cmu.edu. Accessed on 2010­01­28. External links What is the basis for the CPK color scheme? Which colors is used for which atom? (http://www.biosino.org/ mirror/www.ncbi.nlm.nih.gov/Structure/cn3d/cn3dfaq.html#colorCPK) Physical Molecular Models (http://www.netsci.org/Science/Compchem/feature14b.html) Retrieved from "https://en.wikipedia.org/w/index.php?title=CPK_coloring&oldid=744747579" Categories: Molecular modelling Colors This page was last modified on 17 October 2016, at 05:30. Text is available under the Creative Commons Attribution­ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non­profit organization. https://en.wikipedia.org/wiki/CPK_coloring 6/6.